Wahlgren N, Ahmed N, Dàvalos A et al.
Karolinska Institutet, Stockholm, Sweden.
Lancet 2008;372:1303–9.
[2] Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke.
Hacke W, Kaste M, Bluhmki E et al.
Universität Heidelberg, Heidelberg, Germany.
N Engl J Med 2008;359:1317–29.
Editor’s note: A condition of licensing alteplase (a recombinant tissue plasminogen activator) in the European Union for the treatment of acute ischemic stroke was that the Safe Implementation of the Thrombolysis in Stroke Monitoring Study (SITS-MOST) registry of patients would be set up to monitor the safety of treatment. A report from this registry, published in 2007 (
Lancet 2007;369:275–82), demonstrated the safety of intravenous alteplase given within 3 h of symptom onset in standard clinical practice. Patients continue to be recruited to the SITS-MOST database, and Wahlgren
et al. have now published their analysis of patients who were treated outside the licensed time window, between 3 and 4.5 h after symptom onset [1]. This is an area where the benefits of thrombolysis are less well-established, and the risk of symptomatic intracranial hemorrhage may be greater.